Complementary metal-oxide-semiconductor (CMOS) technologies can be used for constructing integrated circuits of many types. For example, CMOS technology is used in microprocessors, microcontrollers, static RAM, and other digital logic circuits, as well as analog circuits such as image sensors, data converters, and highly integrated transceivers for many types of communication.
In CMOS technologies, a metal gate electrode is formed on top of a gate dielectric material, e.g., high-k dielectric material, which, in turn, is formed on top of a semiconductor material. Aluminum can be used as the metal gate material, in combination with a workfunction metal acting as a liner. A contact can then be formed adjacent to the metal gate material. The contact can be, for example, a borderless or self-aligned contact.